The proposed work covers two main areas and two subsidiary areas. The main areas are: 1) Comparative effects of alkylating chemotherapeutic agents on the initiation, elongation and transport of mRNA from nucleus to cytoplasm. Evaluation of alterations due to chemical attack in DNA, its correlation with the mode of drug action and effectiveness in a number of tumor cell lines. 2) Detailed analysis of mitochondrial mRNA's to establish origin (i.e., mt or nuclear) in various normal and neoplastic cells. Identification of mt synthesized peptides related to particular mRNA electrophoretic peaks. Analysis of the effects of alkylating agents on the kinds and numbers of messages transcribed and translated in mitochondria. Subsidiary areas include: 1) Study of the specialized transport of chemotherapeutic agents as a means of potentiating anti-tumor action. 2) Detailed comparison of the altered bases following mono-vs bi-functional in vivo attack on DNA.